Electrical device having a hollow housing with one or more contact elements mounted thereon



Jan. 19, 1965 N. FRANTZ ETAL. 3,166,649

ELECTRICAL DEVICE HAVING A HOLLOW HOUSING WITH ONE OR MORE CONTACT ELEMENTS MOUNTED THEREON Filed Feb. 12, 1961 4 Sheets-Sheet 1 IN VEN TORS,

. NICHOLAS FRANTZ BY NOBU KAWAMOTO OLSEN m s 'g t-t f rggqsou Jan. 19, 1965 N. FRANTZ ETAL 3,166,649 ELECTRICAL DEVICE HAVING A HOLLOW HOUSING WITH ONE OR MORE CONTACT ELEMENTS MOUNTED THEREON Filed Feb. 12, 1961 4 Sheets-Sheet.2

E LET- 5 98 E-T-Ezfi 39 6 38 INVENTORS.

NICHOLAS FRANII'Z y NOBU KAWAMOTO OLSEN AND STEPHENSON xrroansva Jan. 19, 1965 N. FRANTZ ETAL 3,156,649

ELECTRICAL DEVICE HAVING A HOLLOW HOUSING WITH ONE I OR MORE CONTACT ELEMENTS MOUNTED THEREON Filed Feb. 12, 1961 4 Sheets-Sheet s E I- CEr:l-D

ELE: 3-3.-

INVENTOR. NICHOLAS FRAN'IZ By NOBU KAWAMOTO OLSEN AND STEPl-ENSON ATTORN s 1965 N. FRANTZ ETAL 3,166,649

ELECTRICAL DEVICE HAVING A HOLLOW HOUSING WITH ONE OR MORE CONTACT ELEMENTS MOUNTED THERE-ON Filed Feb. 12, 1961 4 Sheets-Sheet 4 INVENTORS NICHOLAS FRANTZ NOBU KAWAMOTO OLSEN um STEPHENSON xrronuzva United States Patent irce This invention relates generally to electrical devices and more particularly to an improved electrical jack which is adapted to be manufactured in very small sizes.

Miniature jacks are usually merely copies in reduced size of standard jacks. As a result, these miniature jacks have been diflicult to assemblebecause of the small size of the parts, hand adjustment of the parts has been required, non-uniform operating and contact pressures have resulted, and the jacks have had a shortened oper-' ating life. Accordingly, it is an object of this invention to provide an improved jack which is adapted to be man-' ufactured in small sizes, is readily assembled, and has contact springs which snap into a housing. Another object is to provide an electrical jack in which adjustment of the jack parts is eliminated, uniform contact and operating pressures are obtained at all times, and the c0ntact springs are enclosed in the jack housing so that they cannot be accidentally displaced or deformed.

A further object of this invention is to provide an electrical jack of the above type in which the jack is completely insulated from its metal mounting panel without requiring any insulation washers or bushings.

Further objects, features and advantages of this invention will become apparent from a consideration of the following description, the appended claims and the accompanying drawing in which:

FIGURE 1 is a longitudinal sectional 'view ofone form of the jack of this invention;

FIGURE 2 is an elevational view of one end of the jack shown in FIGURE 1; s

FIGURE 3 is an elevational view of the opposite end of the jack shown in FIGURE 1;

FIGURE 4 is a fragmentary sectional view looking substantially along the line 4-4 in FIGURE 1;

FIGURE 5 is a longitudinal sectional view of the jack of this invention looking substantially along the line 55 inFIGURE 1; s

FIGURES 6 and 7 are reduced transverse sectional views of the jack of this invention looking substantially along the lines 6-6 and 77, respectively," in FIG- URE 1;

FIGURE 8 is a fragmentary longitudinal sectional view of one modified form of the jack of this invention;-

FIGURE 9 is a fragmentary longitudinal sectional view of anothermodified form, of'the jack of this invention;

FIGURE 10 is a longitudinal sectional view of vstill 7 another modified form of the jack of this invention;

FIGURE 11 is a longitudinal sectional viewsof the form of the jacket this invention shown in FIGURE 10 looking substantially along the line 1111 in FIG- URE 10; j 7

FIGURE 12 is a longitudinal sectional View 'of still another modified form of the jack of this invention;

FIGURE 13 is a longitudinal sectional view of the jack shown in FIGURE 12 showing a mating plug inserted into the jack; and i V v FIGURE 14 is a transverse sectional views of the jack shown in FIGURE 12 looking substantially along theline 14-14 in FIGURE 12. p l e I 1 With reference to the drawing, a transfer circuit type jack, indicated genera-11y at'10, is illustrated in FIGURES 1-7, inclusive, as including a housing 12 formed of dielectrical material, preferably a molded phenolic. The

housing 12 is of a one-piece hollow construction having an open end 14, a closed end 16 and an annular side wall 18 which extends between the ends 14 and 16. The housing 12 is formed with a longitudinally extending cavity 20 which extends inwardly of the housing 12 from the open end 14 thereof, and an end wall 22 which includes an inwardly extending integral projection 24 (FIGS. 1 andi4). The side wall 18 is formed, on transversely opposite sides of the housing 12,'w-ith inwardly extending wall portions 25 which project into the cavity 20 from opposite sides and having their opposite sides curved, as shown at 27.

Adjacent its open end 14, the housing 12 is formed with an integral external collar or rim 26 which constitutes a transversely outwardly extending projection on the housing 12. On transversely opposite sides of the housing the collar 26 is formed with a pair of slots 28 which extend longitudinally of the housing 12 adjacent the outer side of wall 18. ,A pair of notches 30 are formed in the side wall 18'at the open end 14 of the housing 12 so that each notch 30 extends between a slot 28 and the cavity 20. A pair of slots 32 (FIG. 7), of a reduced width relative to the notches 30 and the slots 28, are formed in the side wall 18 so that they extend inwardly thereof from the notches 30. The slots 32 merely facilitate forming of the slots 28 andmay be omitted if desired.

Three spring contact elements 34, 36 and 38 constructed from flat spring material and hereinafter referred to as the shunt, tip, and make elements are mounted on the housing 12 so that they project into the cavity 20. The shunt spring contact element 34 is of a generally U- shape and includes a base portion 40 which is positioned in one of the notches 30, and an outer leg portion 42 which extends through the slot 28 that communicates with the notch 30 in which the base portion 40 is positioned.- The leg portion 42 is provided with an aperture 44 to adapt it for connection to a suitable conductor. An irregularly shaped inner leg portion 46 of the element 34 projects'into the cavity 20 and is formed intermediate its ends with ,a laterally extending contact section 48 which a is return bent upon itself. The leg portion 46 is of a length such a straight end portion 50 extends to a position one one side 51 of the end wall projection 24 between the side wall portions 25.

The tip spring contact element 36 is likewise of a gen erally U-shape and includes a base portion 50 which is,

tact element 34 and is of a length to engage the end wall projection 24 on the side 62 opposite the leg portion 46. The spring contact elements 34 and 36 are formed from flat stripsof spring metal each of which is stressed when bent to the illustrated shape so that its leg portions tend to move in directions away from each other. Consequently, the leg portions 42 and 46 of the shunt spring contact element 34 tend to move away from each other thereby facilitating a snap assembly of the element'34 with the housing 12. In assembly, the outer legportion 42 is extended through the slot 28 and the leg portion 46 is moved inwardly of the cavity 20 and during such movement .is held in a position adjacent the housing side wall 18 so that the end section 50 of the leg portion 46v will be on the side 51 of the projection 24. On release of the leg portion 46 the section 50 springs or snaps into en- Patented Jan. 19, 1965,

d gagement with the side 51 of the projection 24. All of the snap action of the element 34 is concentrated in the leg portion 46 since the leg portion 42 is restrained against movement away from the leg portion 46 by the collar 26.

The tip spring contact element 36 is similarly assembled with the housing 12 by extending the leg portion 52 through a slot 28 concurrently with holding the leg portion 56 adjacent the housing side wall 18 so that the end section 60 of the leg portion 56 will clear the projection 24. On release of the leg portion 56, it will snap toward the projection 24 and the section 60 will contact the section 48 of the shunt element 34. The elements34 and 36 are shaped so thatthe sections 48 and 60, thereof, snap into engagement with the desired contact pressure when the elements 34 and 36 are assembled with the housing 12. The element having the stronger spring force overpowers the other element and moves it in a direction away from the projection 24 until the stronger element engages the projection 24. In the illustrated embodiment of the jack of this invention, the tip element is stronger so that when the elements are assembled with the housing 12 as shown in FIGURE 1, the element 36 engages the projection 24 and the leg portion 46 of the element 34 is spaced from the projection 24.

The make spring contact element 38 is likewise of a generally U-shape having a base portion 62 which straddles the collar 26 at the open end of the housing .12, an outer leg portion 64 which is provided with an aperture 66 to adapt it for connection to the conductor, and an inner leg portion 68 which projects into the cavity 20 toward the housing end wall 22. The 'base portion 62 and the leg portion 68 are of a width only slightly less than the distance between opposite portions of the side wall '13 and are much wider than the base portion 50 and leg portion 56 of the tip spring contact element 36 (FIGS. and 7). The element 38 is provided with an elongated opening 70 through which the leg portion 56 of the element 36 extends so that the elements 36 and 38 are out of contact when they are initially assembled with the housing 12. As a result of the formation of the element 38 with the opening 70, the leg portion 68 thereof has narrow side sections 72 which extend along the inner side of the housing side wall 18 and are connected at their inner ends by a transversely extending end Contact section 74 which is return bent upon itself in the direction of the leg portion 56 of the element 36. The section 74 is of a width to extend across the cavity 2t) and engage both side wall portions 25 so that the leg portion 68 is confined between the side wall 18 on one side of the housing 12 and the wall portions 25.

An insulator washer 76, of a rectangular shape corresponding substantially to the rectangular shape of the end of the housing 12 having the collar 25, and provided with a central aperture 78 is positioned againstthe open end 14 of the housing 12 so as to maintain the spring contact elements 34, 36 and 38 in assembled positions on the housing '12. The washer 76 may be formed of any suitable dielectrical material and at the present time a molded phenolic is preferred, A support sleeve 80 for a mating plug, indicated at 82 in dotted lines in FIGURE 1, is provided with external threads 84 and is formed with a reduced diameter inner end portion -86. A rectangular flange S8 is formed on the sleeve 89 adjacent the inner end portion 86 and projects radially outwardly therefrom. A terminal clamp 99 includes a rectangular plate portion 92 provided with a rectangular off-set portion 94 formed with a central opening 96of a size corresponding substantially to the outer diameter of the sleeve 8d. The clamp 26 also includes a pair of clamping fingers 9% formed integral with the plate portion 92 and extending outwardly from opposite sides thereof. An apertured leg sometimes referred to as a sleeve terminal because current can flow through it from sleeve 80, is formed integral with the plate portion 92 and is adapted to be attached to a suitable conductor, usually for grounding purposes;

I In the assembly of the jack 10, the make spring contact element 38 is initially assembled with the housing 12, as shown in FIGURE 1, with the leg portion 68 confined between the side wall 18 and the wall portions 25, and the base portion 62 confined in a notch 39 (FIG. 6) formed in the end of the housing 12 so that it extends between the cavity 20 and the outer side of the collar 26. The shunt spring contact element 34 and the tip spring contact element 36 are snapped into the housing as previously described so that the leg portion 56 of the element 36 extends through the opening '76 in the element 38. The insulator washer 76 is positioned against the end of the housing 12 so as to prevent relative movement of the elements 34, 36 and 32% in a direction longitudinally of the housing 12, and to confine the elements in their respective notches 3i) and 39. The leg portions 42 and 52 of the elements 34 and 36 are of a width corresponding substantially to the width of the slots 28 through which they extend so that the collar 26 in which the slots 28 are formed eifectively prevents relative movement of the ele-' ments 34 and 36 in a direction transversely of the housing 12. As shown in FIGURE 7, the leg portion 68 of the element 38 is of a width only slightly less than the width of the rectangular cavity 2% so that the housing side wall 18 also prevents relative movement of the element 38 with respect to the element 36 sufiicient to provide for contact of these elements. The reduced end portion 36 of the sleeve projects through the opening '78 in the insulator washer '76 to provide for alignment of these members, and the off-set portion 94 of the clamp 90 engages the tlange 88 on the sleeve 89 and maintains it against the Washer 76. The clamping fingers 98 extend through grooves 99 in the collar 26 and have their end portions 1% bent inwardly and against the end 134 of the collar 26.

In the assembled jack 1%), the elements 34, 36 and 38 are positively held in desired positions, the operating leg portions of the elements are fully enclosed by the housing 12 and no adjustment of the elements 34 and 36 is required since they snap into the housing 12, or the element 33 because it is confined by the wall portions 25. When the mating plug 82 is inserted into the sleeve so as to project into the cavity 20, the end of the plug engages the laterally bent section 58 of the element 36 and moves the leg portion 56 of element 36 toward leg portion 68' of element 38, so as to break the contact of the elements 34 and 36. The construction of the tip spring element with the transversely bent section 58 enables it to lock into a groove 83 in the plug 82 when the plug is fully inserted. When the plug 82 is fully inserted, the section 60 of the tip spring element 36 has been moved into contact engagement with the contact section 74 of the make spring 33 as shown in broken lines in FIGURE 1.

A modified form of the jack of this invention is illustrated in FIGURE 8 and indicated generally at 10a. The jack 10a is of closed circuit type as contrasted to the transfer circuit type jack illustrated in FIGURES 1-7, inclusive, and is identical to the jack 10 except that the make spring contact element 38 in the jack 10' 'is omitted in the jack that. In all other respects, the jacks 10 and 16a are identical and, therefore, identical numerals are used to designate identical parts in the two jacks. In the jack 1163a, when a plug, like the plug 82, is inserted in the sleeve 80 so that it projects into the cavity 20, it engages the tip spring element 36 and moves it out of its normal engagement with the shunt spring element 34. As a result, the circuit which is normally closed by the contact of the elements 34 and 36 is broken when the plug is inserted in the jack 16a.

Another modified form of the jack of this invention is illustrated in FIGURE 9 and indicated generally by the numeral 10b. The jack 1% is of open circuit type, as contrasted to the transfer circuit type jack 10 previously described, and is identical to the jack 10 except that the shunt'spring contact element 34 and the make spring contact element 38 are omitted in the jack 16b.

Consequently, identical numerals are used on the jack b to indicate parts which are identical to the similarly numbered parts in the jack 10. When a plug like the plug 82 is inserted in the support sleeve 86 for the jack 16b so that its projects into the cavity 20, the tip of the plug engages the contact element 36 so that current can flow therebetween. When the plug is withdrawn so that it is out of engagement with the element 34 contact of the plug tip and element 36 is broken. In all of the jacks 10, 10a and ltlb when the plug 82 is inserted in the sleeve 81 the shank of the plug, which is insulated from the tip, engages the sleeve 80 so that it is in electrical contact therewith. I

Another modified form of the jack of this invention is shown in FIGURES 10 and 11 and indicated generally by the numeral 10c. The jack 16c is also of transfer circuit type and includes a hollow housing 12% of dielectric material and having a cavity 121, three spring contact elements 122, 124 and 126 mounted on the housing 121), an insulator washer 123, a support sleeve 131), and a clamp 132. The housing 120 is formed at its open end with pairs of transversely opposite notches 134 and is provided with an enlarged external collar 136 formed with slots 138 which communicate at their ends with the notches 134. An end wall 140 for. the housing 120 is formed with a pair of grooves 142 and 144 which are adjacent the housing side wall 146 on transversely opposite sides of the housing.

The shunt spring contact element 122 is of substantially U-shape and is formed with an elongated opening 123. The element 122 includes a split base portion 148 which is positioned in a pair of notches 134, an outer leg portion 150 which extends through the slot 138 that communicates with notch 134 and a split inner leg portion 152 which is of generally V-shape and terminates in a straight section 154 which connects the split portions and is projected into the groove 142. The leg portion 152 is formed with a pair of relatively converging sections 156 which extend transversely into the housing 121) and are connected by a curved contact section 160.

The tip spring contact element 124 is likewise of a generally U-shape including a split base portion 162 which is disposed in a pair of notches 134, an outer apertured leg portion 164 which extends through a slot 138, and an inner leg portion 166 which projectsinto the housing 126 in a direction toward the shunt spring contact element 122 positioned on the transversely opposite side or" the housing 120. The element 124 is provided with an elongated. opening 168 which extends through the base portion 162 and the leg portion 166 and terminates short of the terminal end 170 of the leg portion 166'which is return bent upon itself for contact purposes. The leg portion 166 is of a width only slightly less than the width of thecavity 121 so that it is restrained against movement transversely of the hous ing 120 by the side wall 146 as well as the notches" 134. As shown in FIGURE 10, the section 176 of the element 124 is normally engageable with the section 160 of the element 122, by virtue of the tendency of these sections to spring toward each other.

The make spring contact element 126 is also generally U-shape and includes a' base portion 172 which is sufliciently narrow to extend through the opening 168 in the tip spring contact element 124 and is positioned in a notch 173 formed in the open end of the housing 121 so that it extends from the outer side of the collar 136 to the cavity 121. The element 126 includes an outer apertured leg portion 176 and an inner leg portion 178 which is substantially parallelto the housing side wall 146 and projects into the groove 144. The spring contact elements 122 and 126 are initially formed from flat spring parts which are stressed when the elements 122 and 126 are formed so that the leg portions of these elements tend to move apart. Consequently, when'the ele-.

6 ment 126 is extended through a slot 138 so that its inner leg portion 152 vextends into the housing 120, the inner end 154 of the inner leg portion 152 snaps against the housing end wall 146 at the inner side of 'the groove 142. The element 124 is similarly stressed so that the inner leg portion 166 thereof tends to spring toward the element 122. The spring in the inner leg portions 152 and 166 of the elements 122 and 124 provides for the engagement of the sections 1611 and 176, respectively, thereof with the desired contact pressure therebetween. In the illustrated embodiment of the jack 160, the spring in the leg portion 166 overpowers the spring in the leg portion 152 so' that the leg portion 152 is moved out of engagement with the end wall 140 at the inner side of the groove 142. The inner leg portion 178 of ele ment 126 is assembled with the housing so that it projects into the groove 144 and is urged against the housing at the inner side of the groove 144.

The clamp 132 is assembled with the sleeve 136 and the insulator, washer 128 like the terminal clamp 90 is assembled with the corresponding parts in the jack 10,

to clamp the washer 128 and the sleeve 130 to the open end of the housing 121 and maintain the elements 122, 124 and 126 in assembled positions on the houstured for connection to a suitable conductor.

The principal advantage of the jack lilc is its small size, particularly its length measured in a direction longitudinally of the housing 126, namely, the distance between the open and closed ends of the housing. The

jack can be constructed with this dimension reduced because of the configuration of the spring contact ele ments 122 and 124. .Each of these elements has an elongated opening formed therein so that the portion of the element which is moved during use of the jack 160 can readilydeflect, because of its reduced mass and the reduced width of the metal in the element, without any danger of a permanentv set in the element when it is used over a prolonged service life. When a mating plug, like the plug 82 shown in broken lines in FIG. 10, is inserted in the sleeve 13t1so thatit projects into the housing 120, the tip of the plug engages the end section 179 of the leg portion 166 of the element 124 and moves the section toward the make element leg 1'78 so that when the plug is fully inserted, as'shown in broken lines in FIGURE 10, the section 170 is in firm contact engagement with the make terminal leg portion 178. The plug extends through the opening 123 and between the side portions of the shunt element 122 so that it does not contact the shunt element 122, which, when the tip element has been moved toward the make element springs inwardly into a position in which the 'end section 154 engages the side wall of the groove 142.

Still another form of the jack of this invention,'indicated generally at 10a, is illustrated in FIGURE 12. The jack 1% is of transfer circuit type, like the jack 1%) previously described and like numerals are used on the jack 10d to indicate like parts on the jack 1%. The jack 10d includes a housing 12, spring contact elements 34, 36 and 3 8 and an insulating washer 76 assembled like the corresponding parts are assembled in the jack 10. An externally threaded support sleeve 200, formed of a dielectric material, is provided with a reduced diameter inner end portion 202 which projects through the central opening '78 in the washer 76. Adjacent the end portion 262, the sleeve 290 is formed with a flange 204 which is positioned against the washer '76 and is 7 formed with a radial slot 2% which extends from the radially outer edge 298 of the flange 2% to the hollow interior of the sleeve 26%. The slot 206 has transversely extending portions 297 so that it is in substantially the shape of a cross (FIG. 14).

A clamp 210, having a central opening 212 through which the sleeve 280 projects, abuts the flange 204 and has a pair of clamping fingers 213 clamped to the collar 26 on the housing 12 like the fingers 98 are clamped to the collar 2a in the jack 10. A sleeve terminal 214, formed of a fiat spring material, has a pair of oppositely extending leg portions 216 and 218 which are connected by a cross shape portion 220. The portion 220 is positioned so that it extends radially of the sleeve 200 and is disposed in the slot 220 so that the leg 216 is positioned outside the sleeve 2% and the housing 12 and is provided with an aperture 222 to adapt it for connection to a suitable conductor. The leg 218 is bowed intermediate its ends and is positioned in a slot 224 formed in the inner surface of the sleeve 20% and extended longitudinally thereof. Because the leg 218 is bowed, an intermediate portion thereof projects radially inwardly of the sleeve 2% into the path of a plug, like the one shown at 82 in FIGURE 3, so that when the plug is inserted in the sleeve 200, the shank of the plug is in contact engagement with the leg 218. The shank is readily grounded by connecting sleeve terminal 214 to ground.

The primary advantage of the jack 16a is the insulation of the sleeve 260 from the sleeve terminal 214, which is accomplished by forming the sleeve 200 of a dielectrical material. By virtue of this construction, the jack is completely insulated from a metal mounting panel in which the sleeve 20% is mounted, without requiring any additional insulating washers, bushings, or the like. The jack 19d is mounted by projecting the externally threaded sleeve 20 through an opening in the mounting panel and then threading a nut onto the sleeve 2% so as to clamp it to the mounting panel.

From the above description, it is seen that this invention provides electrical jacks a-a', inclusive, which are readily assembled and are adapted to be manufactured in very small sizes because of the compact arrangement of the spring contact elements. The jacks are readily assembled because of the snap on mounting of some of the contact elements on the housing and, by virtue of this mounting of the contact elements, they are positively maintained in their assembled positions and no adjustment is required to assure a uniform contact pressure of the elements. Because the contact elements are enclosed at their working ends in their housing, they cannot be displaced or deformed during handling and shipping of the jacks. The jacks are readily manufactured so that the mounting sleeve can be placed in current conducting engagement with the mounting panel (FIGURES 1-11, inclusive) or so that the mounting sleeve is insulated from the mounting panel (FIGURES 12-14, inclusive).

It will be understood that the specific construction of the improved electrical jacks which are herein disclosed and described is presented for purposes of explanation and illustration and is not intended to indicate limits of the invention, the scope of which is defined by the following claims.

What is claimed is:

1. In an electrical device, a hollow housing having a pair of ends and a longitudinally extending side wall extending between said ends, a pair of spring contact elements, said housing having means on the outer side of said side wall on transversely opposite sides of the housing for supporting said spring contact elements, each of said spring contact elements being of a generally U-shape having a base portion and a pair of leg portions which tend to assume relatively diverging positions, said supporting means providing for the mounting of said 8 contact elements so that one leg portion for each element is maintained in a supported position outside said housing and the other leg portion extends into said housing into resilient contact engagement with the corresponding leg portion of the other element.

2. In an electrical device, a hollow housing having a pair of ends and a longitudinally extending side wall extending between said ends, said housing having means thereon forming a longitudinally extending slot disposed transversely outwardly of said side wall and extending in a direction generally longitudinally of said housing, a spring contact element of generally U-shape having a base portion and a pair of leg portions which tend to assume relatively diverging positions, said base portion straddling said side wall at one of said ends of the housing and one of said leg portions being located outside said housing and extending through said slot in a direction toward said opposite end of the housing, the other one of said leg portions extending inwardly of said housing in a direction diverged with respect to said one leg portion, and means in said housing engaging said other leg portion so as to limit movement thereof in a direction away from said one leg portion.

3. In an electrical device, a hollow housing having an open end and a closed end and a longitudinally extending side wall extending between said ends, said housing having means thereon forming a slot disposed transversely outwardlyv of said side wall and extending in a direction longitudinally of said housing from said open end thereof, a spring contact element of generally U-shape having a base portion and a pair of leg portions which tend to assume relatively diverging positions, said base portion straddling said side wall at said open end of the housing and one of said leg portions extending through said slot in a direction toward said opposite end of the housing, the other one of said leg portions extending inwardly of said housing in a direction diverged with respect to said one leg portion, and means on said closed end of the housing engaging said other leg portion so as to limit movement thereof in a direction away from said one leg portion.

4. In an electrical device, a longitudinally extending one piece housing having an open end and a closed end, a pair of spring contact elements mounted on transversely opposite sides of said housing adjacent said open end thereof, each of said elements having a portion thereof extending inwardly of said housing, said portions being spring urged in directions into engagement with each other, and projection means on said closed end of said housing engaged with one of said portions for, limiting movement of said one of said portions in a direction toward said other portion on movement of said other portion away from said one portion.

5. In an electrical device, a longitudinally extending housing having an open end and a closed end, a pair of spring contact elements mounted on transversely opposite sides of said housing adjacent said open end thereof, each of said elements having a portion thereof extending inwardly of said housing, said portions being spring urged in directions into engagement with each other, and means on said closed end of said housing engageable with one of said portions for limiting movement of said one of said portions in a direction toward said other portion on movement of said other portion away from said one portion.

6. In an electrical device, a longitudinally extending housing having an open end, a pair of spring contact elements mounted on transversely opposite sides of said housing adjacent said end thereof, each of said elements having a portion thereof extending inwardly of said housing, said portions being spring urged in directions into engagement with each other, and means on said housing limiting movement of one of said portions in a direction toward said other portion on movement of said other portion away from said one portion.

7. In an electrical device, a hollow housing having an open end and a closed end and a longitudinally extending side wall extending between said ends, an inwardly extending projection on said closed end, .a pair of spring contact elements positioned on transversely opposite sides of said housing, each of said elements being of a generally U-shape and including a base portion which straddles said side wall at said open end of the housing and a pair of leg portions which extend in the direction of said closed end and are spring biased so that they tend to diverge, means on the outside of said housing engaging said contact elements so as to restrain movement of the leg portions outside said housing away from said housing ahd provide for a springing of the leg portions inside said housing toward each other, said leg portions inside said housing being of a configuration to engage each other and of a length to engage said projection 'to limit movement of each of said inside leg portions toward the other inside leg portion. I r

8. In an electrical device, a hollow housing having an open end and a closed end and a longitudinally extending side wall extending between said ends, an inwardly extending projection on said closed end, a pair of spring contact elements positioned on transversely opposite sides of said housing, each of said elements being of a generally U-shape and including a base portion which straddles said side wall-at said open end of the housing, and a pair of leg portions which extend in the direction of said closed endand are spring biased so that they tend to diverge, saidahousing having slots formed therein and disposed outside said side wall, each of said contact elements having one of its leg portions disposed in one of said slots so that movement of the leg portions outside said housing in a direction away from said housing is restrained and the leg portions inside said housing spring toward each other, said leg portions inside said housing being of 'a configuration to engage each other and of a} length to engage said projection to limit the movement of each of said inside leg portions toward the other inside leg portion.

9. In an electrical device, ,a hollow housing having an open end and a closed end and a longitudinally extending side wall extending between said ends, a pair of spring contact elements positioned on transversely opposite sides of said housing, each of said elements being of a generally U-shape and including a base portion which straddles said side wall at said open end of the housing and a pair of leg portions which extend in the direction of said closed end and are spring biased so that they tend to diverge, said housing having slots formed therein and disposed outside said side wall,each of said contact ele ments having one of its leg portions disposed in one of said slots so that movement of the, leg portions outside said housing in a direction away from said housing is restrained and the leg portions inside said housing spring toward housing and communicating at one end with said notch,

a spring contact element having a base portion and a pair of leg portions, said base portion being in said notch and one of said leg portions being in said slot so that said projection res-trains said one leg portion against movement toward and away from said other leg portion, said other leg portion extending into said cavity and having at least a portion thereof extending inwardly toward the axisof said' cavity, and a sleeve adapted to support a mating plug engageable with said contact element, said sleeve beingmounted on said one end of said housing in a substantially coaxial relation with said housing.

11. An electrical jack comprising an insulator housing having an axial cavity in one end thereof, said housing having a notch formed in said one end thereof and extending transversely outwardly from said cavity to the outerwall of said housing, a projection on said housing disposed transversely outwardly of said notch, said projection having a slot therein extending longitudinally of said housing and communicating at one end with said notch, a spring contact element having a base portion and a pair of leg portions which tend to spring away from each other, said base portion being in said notch and one of said leg portions being in said slot so that said projection restrains' said one leg portion against movement toward and away from said other leg portion, said other leg portion extending into said cavity and having at least a portion thereof extending inwardly toward the axis of said cavity, means in said housing engageable with said other leg portion for limitingspring movement thereof in. a direction away from said one leg portion, and a sleeve adapted to support a mating plug engageable with said con-tact element, said sleeve being mounted on said one end of said housing ina substantially coaxial relation with said housing;-

12. An electrical jack comprising an insulator housing having an axial cavity in one end thereof, said housing having a notch formed in said one end thereof and extending transversely outwardly from said cavity to the outer wall of said housing, a projection on said housing disposed transversely outwardly of said notch, said projec tion having a slot therein extending longitudinally of said housing and communicating at one end with saidnotch,

a spring contact element having a base portion and a pair of leg portions, said base portion being in said notch and one of said leg portions being in saidslot so that said projection restrains said one leg portion against movement section extending between theside sections of s'aidter minal end, and a sleeve adapted tosupport a mating plug engageable with said contact element, said sleeve being mounted on said one end of said'housing in a substantially coaxial relation with said housing.

13. In an electrical jack, a housing having a longitudinally extending cavity formed in one-end thereof and being formed at said one end with an enlarged external collar, said collar having slots therein on transversely opposite sides of said housing extending longitudinally of the housing, a pair of spaced contact elements, each of said contact elements being of a generally U-shape and including a base portion and a pair of leg portions, each of said contact elements. being mounted onsaid housing so that one of said leg portions extends through one of said slots and the other one of said leg portions extends into said cavity, a sleeve adapted to support a plug for movement into said cavity and into engagement with at least one of said contact elements, and a clamp member engaged with said sleeve and said collar at positions between said slots for clamping said sleeve to said one end of said housing. a

14. In an electrical jack, a housing having a longitudinally extending cavity formed in one end thereof and being formed at said one end with a generally rectangular transversely outwardly extending enlarged portion, said enlarged portion having slots therein on a first pair of transversely opposite sides thereof extending longitudinally of the housing, a pair of spaced con-tact elements,

each of said contact elements being of a generally U-shape and including a base portion and a pair of leg portions;

each of said contact elements being mounted on said housing so that one of said leg portions extends through one of said slots and the other one of said leg portions projects into said cavity, a sleeve adapted to support a plug for movement into said cavity and into engagement with at least one of said contact elements, and a clamp member engaged with said sleeve and a second pair of transversely opposite sides of said enlarged portion for clamping said sleeve to said one end of said housing.

15. In an electrical jack, a housing having a longitudinally extending cavity formed in one end thereof and being formed at said one end with an enlarged external collar, said collar having slots therein on transversely opposite sides of said housing extending longitudinally of the housing, a pair of spaced contact elements, each of said contact elements being of a generally U-shape and including a base portion and a pair of leg portions, each of said contact elements being mounted on said housing so that one of said leg portions extendsthrough one of said slots and the other one of said leg portions extends into said cavity, an insulator washer having one sidethereof engaged with and extending across said one end of said housing, a sleeve adapted to support a plug for movement into said cavity and into engagement with at least one of said contact elements, said sleeve having a radial projection adjacent one end thereof movable into I engagement with the opposite side of said washer, and a clamp member engaged with said sleeve projection and said collar at positions between said slots for clamping said sleeve to said one end of said housing and for retaining said contact elements in predetermined supported positions on said housing.

16. In an electrical jack, a hollow insulator housing having an axis and a pair of ends one of which is open and the other closed, said one end of said housing having a pair of slots formed therein which are generally parallel to said axis, a pair of contact members positioned in said slots and, extending into said housing, a third contact member positioned so that it extends into said insulator at said one end and extends transversely across a portion of said one end in a clearance relationwith said pair of contact members, an insulator washer at said one end of said housing, a sleeve having a flange at one end engaging said washer, and a terminal clamp engaging one side of said flange and said housing so as to clamp said flange and washer between said clamp and housing.

17. In an electrical jack, an insulator housing having an open end and a closed end and a continuous wall extending between said ends, an external collar formed on said wall at said open end of the housing, said collar having slots formed in transversely opposite sides thereof, a pair of contact elements extending through said slots and projecting into said housing into spring contact engagement with each other, an insulator washer having one side abutting said open end of the housing, anvinsulator sleeve positioned adjacent said-cavity for supporting a plug adapted to project into said housing for engagement with at least one of said one contact elements, a third contact element having one portion positioned between said sleeve and the opposite side of said washer and another portion extending into said sleeve for engagement with a plug therein, and a clamp member engaged with said sleeve and said collar for clamping said sleeve,

washer and third contact element to said open end of said housing.

18. In an electrical jack, a hollow insulator housing having a pair of ends one of which is open, said one end of said insulator having a pair of slots formed therein, a pair of spring contact members each having a first portion positioned in one of said slots and a second portion extending into said insulator, said contact members being constructed so that said second portions thereof spring toward each other into contact engagement in said housing, means on said housing engageable with one of said second portions for limiting movement thereof toward said other second portion, a third contact member positioned so that it extends transversely across a portion of said one end in a clearance relation with said pair of contact members and has a leg portion projected into said housing and positioned so that said other second portion is engageable therewith on movement in a direction away from said one second portion, means on said housing engageable with said leg portion for limiting movement thereof in a direction toward'said other second portion,

an insulator washer at said one end of said housing, a sleeve having a flange at one end engaging-said washer, and a terminal clamp engaging one side of said flange and said housing so as to clamp said flange and washer between said clamp and housing member. 

1. IN AN ELECTRICAL DEVICE, A HOLLOW HOUSING HAVING A PAIR OF ENDS AND A LONGITUDINALLY EXTENDING SIDE WALL EXTENDING BETWEEN SAID ENDS, A PAIR OF SPRING CONTACT ELEMENTS, SAID HOUSING HAVING MEANS ON THE OUTER SIDE OF SAID SIDE WALL ON TRANSVERSELY OPPOSITE SIDES OF THE HOUSING FOR SUPPORTING SAID SPRING CONTACT ELEMENTS, EACH OF SAID SPRING CONTACT ELEMENTS BEING OF A GENERALLY U-SHAPE HAVING A BASE PORTION AND A PAIR OF LEG PORTIONS WHICH TEND TO ASSUME RELATIVELY DIVERGING POSITIONS, SAID SUPPORTING MEANS PROVIDING FOR THE MOUNTING OF SAID CONTACT ELEMENTS SO THAT ONE LEG PORTION FOR EACH ELEMENT IS MAINTAINED IN A SUPPORTED POSITION OUTSIDE SAID HOUSING AND THE OTHER LEG PORTION EXTENDS INTO SAID HOUSING INTO RESILIENT CONTACT ENGAGEMENT WITH THE CORRESPONDING LEG PORTION OF THE OTHER ELEMENT. 